Index: dialin/dg/hd_proxy.py
===================================================================
diff -u -rbe5fbabd50dc31e5e5a5e4b99893fb8b92d016bd -rcb8d11b54d3d823181afbdb3717f612e0a533179
--- dialin/dg/hd_proxy.py	(.../hd_proxy.py)	(revision be5fbabd50dc31e5e5a5e4b99893fb8b92d016bd)
+++ dialin/dg/hd_proxy.py	(.../hd_proxy.py)	(revision cb8d11b54d3d823181afbdb3717f612e0a533179)
@@ -18,7 +18,7 @@
 from ..common.msg_defs import MsgIds
 from ..protocols.CAN import DenaliMessage, DenaliChannels
 from ..utils.base import AbstractSubSystem
-from ..utils.conversions import integer_to_bytearray
+from ..utils.conversions import integer_to_bytearray, float_to_bytearray
 
 
 class DGHDProxy(AbstractSubSystem):
@@ -74,19 +74,20 @@
             self.logger.debug("Timeout!!!!")
             return False
 
-    def cmd_fill(self, volume: int = 1500, start: int = 1) -> int:
+    def cmd_fill(self, volume: int = 1500, tgt_fill_flow_lpm: float = 0.8, start: int = 1) -> int:
         """
         Constructs and sends the fill command.
         Constraints:
             DG must be in re-circulate water state of re-circulate mode.
             Given fill to volume must be between 0 and 1950 mL.
 
         @param volume:  unsigned int - volume (in mL) to fill inactive reservoir to.
+        @param tgt_fill_flow_lpm: float - target fill flow rate in L/min.
         @param start: unsigned int - 1 = start fill, 0 = stop fill.
         @return: 1 if successful, zero otherwise
         """
 
-        payload = integer_to_bytearray(volume) + integer_to_bytearray(start)
+        payload = integer_to_bytearray(volume) + integer_to_bytearray(start) + float_to_bytearray(tgt_fill_flow_lpm)
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id,
                                               message_id=MsgIds.MSG_ID_DG_FILL_CMD.value,